The present disclosure relates to an attachment member and a seat equipped with airbag module, and it pertains to an attachment member for attaching a guide member for guiding a deployment direction of an airbag and a seat equipped with airbag module including the attachment member.
Conventionally, a seat in which an airbag module is attached to a side frame of a seat back frame has been proposed as a seat equipped with an airbag module. For example, ends of a trim cover (surface material) are sewn together with respective one ends of two stay cloths (which is hereinafter referred to as guide members) to form a breaking portion of the trim cover. The two stay cloths are pulled from the breaking portion into the inside of the trim cover to wrap the airbag module; thereby, a seat back including this airbag module is entirely covered by the trim cover (for example, see Japanese Patent Publication JP 2013-112186A, Japanese Patent Publication JP 4543270B, or Japanese Patent Publication JP 3978741B).
In particular, Japanese Patent Publication JP 2013-112186A (“the '186 document”) discloses the technique to attach an attachment member, attached to the end of the stay cloth, to a rim of the side frame. Specifically, a groove to be connected with the end of the stay cloth and a groove to be locked to a front rim of the side frame are formed in the attachment member, and these two grooves are formed to extend in parallel with each other. According to the '186 document, the stay cloths allow an expansion pressure of the airbag to be effectively concentrated on a sewn portion that serves as the breaking portion of the trim cover and high deployment performance of the airbag can be maintained. In addition, the stay cloths can be easily attached by using the attachment member.
Further, two listing wires disclosed in Japanese Patent Publication JP 4543270B (“the '270 document”) are located on the opposite side of the airbag module of the side frame to be entwined with each other to form a wire puzzle shape. The ends of the two stay cloths pulled from the breaking portion to both sides of the airbag module are extended to the two listing wires so that the stay cloths wrap the airbag module, thereafter being attached respectively to the listing wires. According to the '270 document, the airbag module is directly wrapped by the stay cloths and the stay cloths can be surely pulled and locked by the listing wires with their respective ends at which the stay cloths are provided. The expansion pressure of the airbag can be effectively concentrated by the stay cloths on the sewn portion that serves as the breaking portion of the trim cover. As a result, the high deployment performance of the airbag can be attained.
However, in the '270 document, the listing wires are provided to be entwined with each other to form a wire puzzle shape; therefore, the listing wires are configured in a complicated manner and an attaching process is complicated. In addition, the listing wires are required to attach the stay cloths to the side frame, resulting in an increase of the size of an area surrounding the side frame; therefore, a more compact structure has been desired.
Accordingly, an attachment member for holding an end of a stay cloth to a side frame without using a listing wire and to more easily fix the stay cloth so that an airbag module is wrapped by the stay cloth is disclosed by Japanese Patent Application No. 2012-288619. Specifically, a portion of the attachment member is fitted into a substantially rectangular attachment hole of the side frame to thereby fix the end of the stay cloth to the side frame. According to Japanese Patent Application No. 2012-288619, a listing wire is not used; therefore, the attachment member is more easily fitted into the attachment hole of the side frame and an increase of the size of an area surrounding the side frame is avoided.
Further, Japanese Patent Publication JP 3978741B (“the '741 document”) discloses the seat equipped with airbag module in which a support bar and two wires which are configured by wire rods of piano wire rods or the like are used to attach the stay cloths to the side frame. Specifically, in order to attach the two stay cloths to the side frame, firstly, respective one ends of the two stay cloths are sewn to the surface material, and the other end of one of the two stay cloths is sewn to one of the two wires and the other end of the other of the two stay cloths is sewn to the other of the wires. Next, the wires are respectively hooked to the support bar to be entwined with the support bar that is fixed to the side frame. Furthermore, the stay cloth disclosed in the '741 document is fan-shaped in a manner to spread out fanwise from a portion sewn to the wire and is formed to cover the airbag module.
In the technique disclosed in the '186 document, a process for attaching the stay cloth to the attachment member is one process which is included in a process for attaching the trim cover to the seat back frame. Therefore, it is necessary to, before completely covering the seat back frame by the trim cover, check whether the attachment member is attached to the stay cloth in a correct procedure. As described above, in the attachment member, the groove to be locked to the front rim of the side frame and the groove to be connected with the end of the stay cloth are formed to extend in parallel with each other. In addition, the front rim of the side frame extends in an up to down direction. Accordingly, in a state where the attachment member is attached to the front rim of the side frame, the groove formed in the attachment member to be connected with the end of the stay cloth extends in the up to down direction. Therefore, in order to check a connected state between the stay cloth and the attachment member after attaching the attachment member to the side frame in a seat width direction, an operator needs to change his/her position to check by shifting a view in the seat width direction at the time of attaching the attachment member to the side frame to a view toward the upper or lower side relative to the attachment member, resulting in low workability. Further, the operation to attach the end of the stay cloth to the side frame by using the attachment member as disclosed in the '186 document is performed in a manner to attach the attachment member to the side frame by pulling the stay cloth in a state where the trim cover is rolled up by the operator. Thus, in a case where the connected state between the stay cloth and the attachment member is checked in a state where the attachment member is attached to the side frame, the trim cover needs to be rolled up. This makes the operation difficult and therefore an instant check is required. Furthermore, a clipped portion may be hidden by the trim cover; therefore, the connected state may not be easily checked.
Further, as disclosed in Japanese Patent Application No. 2012-288619, in order to avoid the stay cloth from being twisted, it is necessary to attach the attachment member by checking its position; therefore, the operation to attach the stay cloth takes time and manufacturing efficiency of the seat may deteriorate. Furthermore, in the structure disclosed in the '741 document where the two stay cloths are attached to the side frame by using the two wires, the stay cloths are sewn to the two wires, respectively, and in addition, the two wires needs to be entwined with the support bar in a state where the stay cloths are pulled. Thus, the number of components is large and workability is low.
Moreover, the stay cloth is formed to have a fan-shape. Therefore, an expansion pressure when the airbag is operated is widely applied to the sewn portion on which the fanwise spread portions of the stay cloths sewn to each other are sewn together with the surface material. Consequently, in an area of the sewn portion in the up to down direction of the seat, it is difficult to control the deployment of the airbag in such a way that the sewn portion breaks at different timing.